高阶FD-WENO格式用于Richtmyer-Meshkov不稳定性数值模拟

用双曲守恒律组的高阶加权本质上无振荡有限差分格式(FD-WENO)求解在众多领域有着重要应用的高马赫数二维流体界面Richtmyer-Meshkov不稳定性问题及激波与气泡相互作用问题,获得了较为理想的数值结果。表明高阶FD-WENO格式的确特别适合于求解这类既具有激波有具有复杂流动结构的流体动力学问题,它比通常的二阶Godunov格式(如PPM等)更为优越。     

发汗控制方程差分方法的误差增长分析

本文讨论发汗控制方程差分方法的误差增长，提出了使方法数值稳定的步长控制准则。     

THREE SOLUTIONS THEOREMS FOR NONLINEAR OPERATOR EQUATIONS AND APPLICATIONS

In this paper, some three solutions theorems about a class of operators which are said to be limit-increasing are obtained. Some applications to the second order differential equations boundary value problems are given.     

An interval method for studying the relationship between the Australian dollar exchange rate and the gold price

This paper proposes an interval method to explore the relationship between the exchange rate of Australian dollar against US dollar and the gold price,using weekly,monthly and quarterly data.With the interval method,interval sample data are formed to present the volatility of variables. The ILS approach is extended to multi-model estimation and the computational schemes are provided. The empirical evidence suggests that the ILS estimates well characterize how the exchange rate relates to the gold price,both in the long-run and short-run.The comparison between the interval and point methods indicates that the difference between the OLS and the ILS estimates is increasing from weekly data to quarterly data,since the lowest frequency point data lost the most information of volatility.     

New estimates of trends in births by birth order in England and Wales

A greater understanding of past, present and future trends in fertility can be gained from analysing trends in birth order; that is whether a birth is a first, second, third or higher order birth. However, under current legislation, birth order information is not collected at registration for births outside marriage and birth order recorded within marriage is not the true birth order. This article presents revised and updated estimates of true birth order. It discusses the construction of the new estimates and presents analysis relating the births by true birth order to the population of women by parity on both a period (fertility in a particular year) and cohort (fertility of women born in a particular year) basis. The new true birth order figures are also compared to the previous set of estimates.     

CHARACTERISTIC ALTERNATING-DIRECTION FINITE ELEMENT METHODS FOR NONRECTANGULAR REGIONS FOR COUPLED SYSTEM OF DYNAMICS OF FLUIDS IN POROUS MEDIA AND ITS ANALYSIS

For coupled system of multilayer dynamics of fluids in porous media, the characteristic alternating-direction finite element methods for nourectangular regions applicable to parallel arithmetic are put forward and two-dimensional and three-dimensional schemes are used to form a complete set. Some techniques, such as calculus of variations, isoparametric transformation, patch approximation, operator-splitting, characteristic method, negative norm estimate, energy method, the theory of prior estimates and techniques are used. For the nourectangular regions case, optimal order estimates in L^2 norm are derived for the error in the approximation solution. Thus the well-known theoretical problem has been thoroughly and completely solved. These methods have been successfully used in multilayer oil resources migration-accumulation numerical simulation.     

CHARACTERISTIC FINITE DIFFERENCE METHODS FOR POSITIVE SEMIDEFINITE PROBLEM OF TWO-PHASE(OIL AND WATER)MISCIBLE FLOW IN POROUS MEDIA

Numericalsimulationoftwo-phase(oilandwater)miscibleflowinporousmediaisthe'mathematicalfoundationinenergyproblems.Forapositivedefiniteproblem,thefamousmathematicianandinitiatorofnumericalsimulationofoildeposit,J.Douglas,Jr.putforwardthefamouscharacteristicfinitedifferencemethodll'2].However,fornumericalanalysistherearoseseriousdifficulties.Heonlystudiedtheperiodiccasesandcoercivelysupposedthedictionmatrixoftheconcentrationequationispositivedefinite.Butinmanypracticalsituationsthediffusionmatr…     

基于主动调度的编码方法及其在JSP中的应用

在对Jobshop问题进行具体描述的基础上,分析了目前利用遗传算法解决Jobshop问题的各种常用的编码方法,提出了一种新的编码方法.该编码方法与主动调度的构成步骤相结合,编码中基因的排列顺序就表示各工序的优先调度顺序,由此产生可行的调度方案,基于该编码方法是以不可重复的自然数为基因进行编码,在遗传操作过程中能采用类似TSP的遗传算子,从而避免了非法调度解的出现.采用该编码方法在遗传算法求解Jobshop问题的过程中,既能满足Jobshop问题的特性,又能体现遗传算法的较强的搜索能力.仿真结果也充分证明了该算法的有效性.     

卫星通信下行链路鲁棒安全波束成形设计

针对多波束卫星通信系统下行链路存在多个窃听者的场景, 在仅已知窃听者大概位置的条件下, 提出了两种鲁棒安全波束成形(beamforming, BF)方案。一种是基于卫星总发射功率受限条件下的系统安全速率最大化准则, 提出了基于广义瑞利商的鲁棒BF方案, 得到了BF权矢量的解析解。另一种是基于安全速率和卫星总发射功率约束下的安全能效最大化准则, 提出了一种分式规划、罚函数以及凸差(difference of convex, DC)规划理论相结合的嵌套迭代算法, 完成鲁棒BF设计。仿真结果表明, 跟传统的非鲁棒BF方案相比, 所提出的两种鲁棒BF方案能够获得更好的安全性能。     

It型随机系统的仿真——离散相似法

研究Ｉｔ＾ｏ型随机系统的仿真，采用离散相似法得到了Ｉｔ＾ｏ型随机系统数值计算的两种差分格式，分析了差分格式的精度和用于Ｉｔ＾ｏ型随机系统仿真的有效性，文末用实例演示了所得方法的应用．     

CLOSURE AXIOMS FOR POSET MATROIDS

An excellent introduction to the topic of poset matroids is due to M. Barnabei, G. Nicoletti and L. Pezzoli. In this paper, we extensively study the closure operators of poset matroids and obtain the closure axioms for poset matroids; thereby we can characterize poset matroids in terms of the closure axioms. Some corresponding properties of combinatorial schemes are also obtained.     

ANISOTROPIC BIQUADRATIC ELEMENT WITH SUPERCLOSE RESULT

The main aim of this paper is to study the convergence of biquadratic finite element forthe second order problem on anisotropic meshes.By using some novel approaches and techniques,theoptimal error estimates are obtained.At the same time,the anisotropic superclose results are alsoachieved.Furthermore,the numerical results are given to demonstrate our theoretical analysis.     

多技能呼叫中心排班算法研究

对多技能呼叫中心的排班问题进行了系统研究.采用考虑顾客放弃的Erlan争A模型计算人力需求,应用动态集合覆盖算法解决多技能排班路由问题,针对多技能优化排班问题设计开发相应的启发式算法,并应用某呼叫中心的实际数据验证了算法的计算效率和优化效果.此外,对不同人力分组方案和不同班时拆分方案进行了一系列试验计算,发现分组细化和班时细分都能够提升排班效果,相比而言班时拆分对排班效果的影响作用更加显著.     

施工导流方案多属性群协商决策

针对异质群体参与的施工导流方案风险型多属性决策问题,分析导流方案决策主体面临不同属性时所对应的偏好尺度和评价效用的差异性,引入群体协商集结理论,提出基于可能度矩阵表征的导流方案群决策策略. 通过对各属性下导流方案决策主体的非一致性、模糊性意见进行协商集结,计算属性权重的协商区间. 基于蒙特卡罗模拟仿真技术,计算随机权重向量下导流方案两两间的优胜概率,得到描述导流方案优胜程度的模糊互补判断矩阵,据此进行备选方案的优先排序,并给出了排序的可信度. 实例验证了该方法的可行性和有效性. 研究为多属性群决策视角下导流方案的优选提供了理论基础和决策支持.     

Deterministic approaches for noncoherent communicationswith chaotic carriers

1.INTRODUCTION Since1990s,chaoticsignalshavebecomepromising carriersincommunications[1].Severalschemeshave beendevelopedsuchaschaoticmasking[2],chaotic modulation[3],chaosspreadingspectrumcommunica tion[4],chaosshiftkeying(CSK)[5].Theadvantages ofutilizingchaoticdynamicsinsuchschemesinclude thebroadband,apparentlystochastic,δ likeautocor relation,natureofthesignalandtheeasewithwhich chaoticdatamaybegenerated.Andtheseschemes exploiteitherthesynchronizationprinciplesforchaot icsignals(…     

Interval-valued intuitionistic fuzzy aggregation operators

The notion of the interval-valued intuitionistic fuzzy set (IVIFS) is a generalization of that of the Atanassov’s intuitionistic fuzzy set. The fundamental characteristic of IVIFS is that the values of its membership function and non-membership function are intervals rather than exact numbers. There are various averaging operators defined for IVIFSs. These operators are not monotone with respect to the total order of IVIFS, which is undesirable. This paper shows how such averaging operators can be represented by using additive generators of the product triangular norm, which simplifies and extends the existing constructions. Moreover, two new aggregation operators based on the ukasiewicz triangular norm are proposed, which are monotone with respect to the total order of IVIFS. Finally, an application of the interval-valued intuitionistic fuzzy weighted averaging operator is given to multiple criteria decision making.     

评价方案优化系统

提出了兼容度和差异度的概念，给出了判断评价方案优劣的标准，为此为契机，构建了兼容度极大化和兼容性，差异度极大极小两化两个数学模型，把多种评价方法的特点兼收并蓄，导出了评价方案的择优方法，最后，用系统的观点，设计并实现了一个融评价方案的创新和选优于一个体的评价方案优化系统，并举两个实例阐明其应用。     

THE IRREGULAR OBLIQUE DERIVATIVE PROBLEM FOR NONLINEAR ELLIPTIC SYSTEMS OF SECOND ORDER

1.TheirregularObliqueDerivativeProblemanditsWell-PosednessforNonlinearEllipticSystemsLabDbean(N 1)-connectedboundeddomaininthez=x ic-planeCwithboundaryFECI(0相似文献   

基于语言量词的变权综合决策方法

利用Borda函数和语言量词将因素状态向量转化为因素的序分值向量,并由序分值向量构造出一类新的激励型状态变权向量,据此建立一种基于语言量词的变权综合决策模型.为说明此决策模型反映语言量词语义的效果,对一些典型语言量词所构造的变权综合决策模型和相应的OWA算子进行了对比分析.最后给出一个应用实例.     

网上超市拆分订单的合并打包优化决策方法

大型网上超市"一地多仓"和"多地多仓"等仓储布局导致"一单多品型"订单被拆分在不同仓库进行拣选并分多次配送给顾客,这就诱发了"高成本、高污染、高扰民"等影响电子商务绿色健康发展的挑战性难题.被拆分订单在多个仓库间的合并打包是化解这一难题的重要手段.本文从化解问题求解难度入手,以提高拆分订单合并打包方案在线生成的科学性和高效性为目标,综合运用组合优化和状态空间搜索理论,围绕拆分订单是否合并打包,选择哪些仓库打包,哪些商品可以合并打包这三个关键问题提出拆分订单合并打包问题的两阶段在线智能优化决策方法.第一阶段归纳总结决策影响因素,制定判定规则,决策合并打包必要性;第二阶段,采用状态空间搜索算法生成备选的合并打包方案集合,将定性的控制策略转换成控制规则纳入方案生成过程来缩减方案空间.数值实验表明,本文提出的合并打包优化策略可有效降低网上超市拆分订单履行成本,理论成果可为指导网上超市或其它拆单现象显著的B2C电商企业的实际合单作业提供借鉴.